European guidelines for quality assurance in colorectal cancer screening and diagnosis: overview and introduction to the full supplement publication

Population-based screening for early detection and treatment of colorectal cancer (CRC) and precursor lesions, using evidence-based methods, can be effective in populations with a significant burden of the disease provided the services are of high quality. Multidisciplinary, evidence-based guidelines for quality assurance in CRC screening and diagnosis have been developed by experts in a project co-financed by the European Union. The 450-page guidelines were published in book format by the European Commission in 2010.  They include 10 chapters and over 250 recommendations, individually graded according to the strength of the recommendation and the supporting evidence. Adoption of the recommendations can improve and maintain the quality and effectiveness of an entire screening process, including identification and invitation of the target population, diagnosis and management of the disease and appropriate surveillance in people with detected lesions. To make the principles, recommendations and standards in the guidelines known to a wider professional and scientific community and to facilitate their use in the scientific literature, the original content is presented in journal format in an open-access Supplement of Endoscopy. The editors have prepared the present overview to inform readers of the comprehensive scope and content of the guidelines.

Patient experiences of colonoscopy, barium enema and CT colonography: a qualitative study

Previous studies of patient experience with bowel screening tests, in particular CT colonography (CTC), have superimposed global rating scales and not explored individual experience in detail. To redress this, we performed qualitative interviews in order to characterize patient expectations and experiences in depth. Following ethical permission, 16 patients undergoing CTC, 18 undergoing colonoscopy and 15 undergoing barium enema agreed to a semi-structured interview by a health psychologist. Interviews were recorded, responses transcribed and themes extracted with the aim of assimilating individual experiences to facilitate subsequent development and interpretation of quantitative surveys of overall satisfaction with each diagnostic test. Transcript analysis identified three principal themes: physical sensations, social interactions and information provision. Physical sensations differed for each test but were surprisingly well tolerated overall. Social interactions with staff were perceived as very important in colouring the whole experience, particularly in controlling the feelings of embarrassment, which was critical for all procedures. Information provision was also an important determinant of experience. Verbal feedback was most common during colonoscopy and invariably reassuring. However, patients undergoing CTC received little visual or verbal feedback and were often confused regarding the test outcome. Barium enema had no specific advantage over other tests. Qualitative interviews provided important perspectives on patient experience. Our data demonstrated that models describing the quality of medical encounters are applicable to single diagnostic episodes. Staff interactions and information provision were particularly important. We found advantages specific to both CTC and colonoscopy but none for barium enema. CTC could benefit greatly from improved information provision following examination.

Flexible sigmoidoscopy and whole colonic imaging in the diagnosis of cancer in patients with colorectal symptoms

BACKGROUND

The aim was to identify the patients with colorectal symptoms most likely to benefit from whole colonic imaging (WCI) to diagnose colorectal cancer and those for whom flexible sigmoidoscopy (FS) may be initially sufficient.

METHODS

This prospective observational study (16 years) included 16 433 newly referred patients with symptoms or signs of colorectal cancer.

RESULTS

Colorectal cancer was diagnosed in 946 patients (diagnostic yield 5.8 per cent), 815 (86.2 per cent) in the rectum or sigmoid (distal) and 131 (13.8 per cent) in the proximal colon. Some 15 829 patients (96.3 per cent) presented with symptoms alone (without iron deficiency anaemia or abdominal mass). Of 787 cancers in these patients, 750 (95.3 per cent) were distal. The prevalence of proximal cancer above and below the age of 60 years was 0.4 per cent (33 of 8249) and 0.1 per cent (four of 7580) respectively. Of 16 256 patients having FS, 5665 (34.8 per cent) had WCI. Of the other 10 591, five subsequently presented with proximal cancers. FS missed ten (1.3 per cent) of 796 cancers.

CONCLUSION

Patients with iron deficiency anaemia or a mass require WCI. However, in patients with symptoms alone, FS detects 95 per cent of cancers, and the diagnostic yield of WCI after FS is very low. Alternative management strategies need to be developed to avoid unnecessary investigations in this low-risk group.

Molecular classification and genetic pathways in hyperplastic polyposis syndrome

Hyperplastic Polyposis (HPPS) is a poorly characterized syndrome that increases colorectal cancer (CRC) risk. We aimed to provide a molecular classification of HPPS. We obtained 282 tumours from 32 putative HPPS patients with >or= 10 hyperplastic polyps (HPs); some patients also had adenomas and CRCs. We found no good evidence of microsatellite instability (MSI) in our samples. The epithelium of HPs was monoclonal. Somatic BRAF mutations occurred in two-thirds of our patients' HPs, and KRAS2 mutations in 10%; both mutations were more common in younger cases. The respective mutation frequencies in a set of 'sporadic' HPs were 18% and 10%. Importantly, the putative HPPS patients generally fell into two readily defined groups, one set whose polyps had BRAF mutations, and another set whose polyps had KRAS2 mutations. The most plausible explanation for this observation is that there exist different forms of inherited predisposition to HPPS, and that these determine whether polyps follow a BRAF or KRAS2 pathway. Most adenomas and CRCs from our putative HPPS patients had 'classical' morphology and few of these lesions had BRAF or KRAS2 mutations. These findings suggest that tumourigenesis in HPPS does not necessarily follow the 'serrated' pathway. Although current definitions of HPPS are sub-optimal, we suggest that diagnosis could benefit from molecular analysis. Specifically, testing BRAF and KRAS2 mutations, and perhaps MSI, in multiple polyps could help to distinguish HPPS from sporadic HPs. We propose a specific model which would have diagnosed five more of our cases as HPPS compared with the WHO clinical criteria.

CT colonography: interpretative performance in a non-academic environment

AIM

To investigate interpretative accuracy and reporting time for radiologists performing computed tomography (CT) colonography in day-to-day non-academic clinical practice.

MATERIALS AND METHODS

Thirteen radiologists from seven centres, who were reporting CT colonography in non-academic daily clinical practice, interpreted a dataset of 15 colonoscopically validated cases in a controlled environment. Ten cases had either a cancer or polyp >10mm; one case had a medium polyp and four were normal. Correct case categorization and interpretation times were compared using analysis of variance to aggregated results obtained from both experienced observers and observers recently trained using 50 cases, working in an academic environment. The effect of experience was determined using Spearman's rank correlation.

RESULTS

Individual accuracy was highly variable, range 53% (95% CI 27-79%) to 93% (95% CI 68-100%). Mean accuracy overall was significantly inferior to experienced radiologists (mean 75 versus 88%, p=0.04) but not significantly different from recently trained radiologists (p=0.48). Interpretation time was not significantly different to experienced readers (mean 12.4 min versus 11.7, p=0.74), but shorter than recently trained radiologists (p=0.05). There was a significant, positive, linear correlation between prior experience and accuracy (p<0.001) with no plateau.

CONCLUSION

Accuracy for sub-specialist radiologists working in a non-academic environment is, on average, equivalent to radiologists trained using 50 cases. However, there is wide variability in individual performance, which generally falls short of the average performance suggested by meta-analysis of published data. Experience improves accuracy, but alone is insufficient to determine competence.

Judgement of the quality of bowel preparation at screening flexible sigmoidoscopy is associated with variability in adenoma detection rates

BACKGROUND AND STUDY AIMS

Adenoma detection rates (ADRs) at screening flexible sigmoidoscopy are known to vary between endoscopists. Variability in the technique used and in the quality of bowel preparation may explain this. The aim of this study was to establish whether there is a relationship between the grading of bowel preparation and the ADR.

MATERIALS AND METHODS

The relationship between the ADR and assessment of bowel preparation was examined using the full United Kingdom Flexible Sigmoidoscopy Screening Trial data set (n = 38 601). The consistency of the bowel preparation classification was then investigated by six experienced endoscopists (video scorers), who examined 260 flexible sigmoidoscopy cases - 20 from each of the 13 trial endoscopists.

RESULTS

Overall, the ADR was significantly higher in flexible sigmoidoscopy examinations with excellent or good bowel preparation ( P = 0.02). However, endoscopists with a higher ADR coded a smaller proportion of their examinations as having excellent/good preparation ( P = 0.002). Video scorers agreed with the trial endoscopists' definition of bowel preparation in 48.9 % of the readings, but they scored the quality of preparation as poorer than the trial endoscopists in 36.4 % and 40.6 %, respectively, in the intermediate-performance group (10 % < ADR < 14 %) and lower-performance group (ADR </= 10 %) in comparison with only 12.9 % in the high-performance group (ADR > or =14 %). There was a significant linear trend between the proportion scored as having poor bowel preparation and the ADR ( P < 0.001), varying from 2.7 % in the higher-performance ADR group to 13.4 % in the lower-performance group.

CONCLUSIONS

Endoscopists with a higher ADR are more likely to be critical of the quality of bowel preparation. Training in judgement processes such as non-acceptance of suboptimal bowel preparation is required in order to ensure universally high standards in screening procedures.

Development of a video assessment scoring method to determine the accuracy of endoscopist performance at screening flexible sigmoidoscopy

BACKGROUND AND AIMS

Variation in the adenoma detection rate (ADR) at flexible sigmoidoscopy screening has been shown to be due to variation in endoscopist performance. There are no objective methods for scoring an endoscopist's performance reliably, and the aim of this study was to develop a valid and reliable objective scoring method using video footage of screening flexible sigmoidoscopies.

METHODS

In a series of five experiments, experienced endoscopists (the scorers) independently scored a sample (n = 43) of the 40 000 flexible sigmoidoscopy extubations recorded as part of the United Kingdom Flexible Sigmoidoscopy Screening Trial (UK FSST). The scoring system, the parameters scored, and their definitions evolved over the course of the five experiments. The initial visual analogue score (range 0-100) used in the first two experiments evolved into a five-point score that ranged from 1 (E, poor) to 5 (A, excellent) in the last three experiments. The final parameters scored were: time spent viewing the mucosa, re-examination of poorly viewed areas, suctioning of fluid pools, distension of the lumen, lower rectal examination, and overall quality of the examination. The first four experiments scored one individual case per endoscopist; in experiment 5, an overall score was awarded for five cases performed by each endoscopist being assessed.

RESULTS

Scoring five cases examined by an individual endoscopist using the A-E grading system was the most reliable method (interclass correlation coefficient 0.89). Cluster analysis demonstrated that the endoscopists in the high-scoring ADR group (ADR 14.7-15.9 %) could be differentiated from those in the intermediate- and low-scoring ADR groups (ADR 8.6-12.6 %).

CONCLUSIONS

An objective scoring system for assessing the accuracy of performance at screening flexible sigmoidoscopy, based on video footage, is described. Endoscopists who might benefit from further training can be identified using this method.

Review article: Population screening for colorectal cancer

Colorectal cancer is a common cancer and common cause of death. The mortality rate from colorectal cancer can be reduced by identification and removal of cancer precursors, adenomas, or by detection of cancer at an earlier stage. Pilot screening programmes have demonstrated decreased colorectal cancer mortality; as a result many countries are developing colorectal cancer screening programmes. The most common modalities being evaluated are faecal occult blood testing, flexible sigmoidoscopy and colonoscopy. Implementation of screening tests has been hampered by cost, invasiveness, availability of resources and patient acceptance. New technologies such at computed tomographic colonography and stool screening for molecular markers of neoplasia are in development as potential minimally invasive tools. This review considers who should be screened, which test to use and how often to screen.

Quality in the technical performance of screening flexible sigmoidoscopy: recommendations of an international multi-society task group

BACKGROUND

Flexible sigmoidoscopy (FS) is a complex technical procedure performed in a variety of settings, by examiners with diverse professional backgrounds, training, and experience. Potential variation in technical quality may have a profound impact on the effectiveness of FS on the early detection and prevention of colorectal cancer.

AIM

We propose a set of consensus and evidence based recommendations to assist the development of continuous quality improvement programmes around the delivery of FS for colorectal cancer screening.

RECOMMENDATIONS

These recommendations address the intervals between FS examinations, documentation of results, training of endoscopists, decision making around referral for colonoscopy, policies for antibiotic prophylaxis and management of anticoagulation, insertion of the FS endoscope, bowel preparation, complications, the use of non-physicians as FS endoscopists, and FS endoscope reprocessing. For each of these areas, continuous quality improvement targets are recommended, and research questions are proposed.

Gender differences in utilization of colorectal cancer screening

OBJECTIVES

To assess the demographic and psychological mediators of gender differences in uptake of flexible sigmoidoscopy (FS) screening for colorectal cancer.

SETTING

A subsample (n=5462) from a large community trial of FS in the UK.

METHODS

Men and women randomized to screening as part of the UK Flexible Sigmoidoscopy Trial were sent a postal questionnaire assessing demographic characteristics and attitudes to screening six months before their screening appointment. Attendance at screening was recorded by the screening centres.

RESULTS

More men than women attended screening (73% versus 67%). The higher male attendance was partially explained by their lower levels of socioeconomic deprivation, higher levels of marital status and lower perceived barriers to screening.

CONCLUSIONS

Contrary to expectations, men were more likely than women to attend FS screening. This was partially explained by socioeconomic and attitudinal differences to screening, but additional research is needed to understand the key aspects of FS screening that will maximize screening uptake in men and women.

Exon 3 beta-catenin mutations are specifically associated with colorectal carcinomas in hereditary non-polyposis colorectal cancer syndrome

BACKGROUND AND AIMS

Activating beta-catenin mutations in exon 3 have been implicated in colorectal tumorigenesis. Although reports to the contrary exist, it has been suggested that beta-catenin mutations occur more often in microsatellite unstable (MSI+) colorectal carcinomas, including hereditary non-polyposis colorectal cancer (HNPCC), as a consequence of defective DNA mismatch repair. We have analysed 337 colorectal carcinomas and adenomas, from both sporadic cases and HNPCC families, to provide an accurate assessment of beta-catenin mutation frequency in each tumour type.

METHODS

Direct sequencing of exon 3 of beta-catenin.

RESULTS

Mutations were rare in sporadic (1/83, 1.2%) and HNPCC adenomas (1/37, 2.7%). Most of the sporadic adenomas analysed (80%) were small (<1 cm), and our data therefore differ from a previous report of a much higher mutation frequency in small adenomas. No oncogenic beta-catenin mutations were identified in 34 MSI+ and 78 microsatellite stable (MSI-) sporadic colorectal cancers but a raised mutation frequency (8/44, 18.2%) was found in HNPCC cancers; this frequency was significantly higher than that in HNPCC adenomas (p=0.035) and in both MSI- (p<0.0001) and MSI+ (p=0.008) sporadic cancers. Mutations were more common in higher stage (Dukes' stages C and D) cancers (p=0.001).

CONCLUSION

Exon 3 beta-catenin mutations are associated specifically with malignant colorectal tumours in HNPCC; mutations appear not to result directly from deficient mismatch repair. Our data provide evidence that the genetic pathways of sporadic MSI+ and HNPCC cancers may be divergent, and indicate that mutations in the HNPCC pathway of colorectal tumorigenesis may be determined by selection, not simply by hypermutation.

Review article: balancing the ideal versus the practical-considerations of colorectal cancer prevention and screening

Colorectal cancer is responsible for over 500 000 deaths annually world-wide. Death from colorectal cancer is preventable, primarily through early diagnosis of disease that has not metastasized. The disease itself may be prevented by the detection and removal of colorectal adenomas, from which more than 95% of colorectal cancers arise. Currently there are several screening methods for the disease. These include faecal occult blood tests, sigmoidoscopy, barium enema and colonscopy as well as emerging methods of virtual colonoscopy and faecal DNA testing. While direct and indirect evidence support the efficacy of these tests they differ from each other in their sensitivity, specificity, cost, and safety. Various professional organizations in different geographical regions of the world have published recommendations on which screening methods to use and when in patients at average- or high-risk. The challenge in reducing the incidence and mortality of this disease lies in increasing accessibility to and compliance with screening and delivery within a quality assured programme.

Use of multidetector-row CT colonography for detection of colorectal neoplasia in patients referred via the Department of Health "2-Week-wait" initiative

AIM

Patients referred under the Department of Health 2-week wait initiative with symptoms of colorectal cancer frequently undergo whole-colon examination. We investigated the use of computed tomography (CT) colonography as an alternative to colonoscopy in this scenario.

MATERIALS AND METHODS

Fifty-four consecutive patients, referred via the 2-week wait initiative and scheduled for colonoscopy, consented to undergo multidetector CT colonography immediately before endoscopy. The site and morphology of any polyp or cancer detected by CT was noted and comparison made with subsequent colonoscopy.

RESULTS

Colonoscopy detected polyps or cancer in 29 patients (53.7%). CT colonography prospectively detected 18 of 41 (44%) polyps of 1-5 mm, three of four (75%) polyps of 6-9 mm, four of four (100%) polyps 10 mm or larger, and five of six (83%) cancers. The missed cancer occurred early in the series and was a perceptive error. The overall sensitivity, specificity, positive predictive value and negative predictive value of CT colonography for cancer and polyps 10 mm or greater on a per patient basis were 90, 100, 100 and 98%, respectively. CT detected one renal cancer and one colonic cancer, initially missed due to incomplete colonoscopy.

CONCLUSION

CT colonography is a robust technique for investigation of symptomatic patients. The learning curve must be overcome for optimal performance.

Observer Variation in the Detection of Colorectal Neoplasia on Double-contrast Barium Enema: Implications for Colorectal Cancer Screening and Training

AIM

To assess inter-observer error for the diagnosis of neoplasia on double contrast barium enema (DCBE) in the light of claims that no additional interpretative training would be needed for implementation in a national screening programme.

MATERIALS AND METHODS

10 experts, 10 consultants, and 10 experienced trainees each reported 20 DCBE studies, of which two showed cancer, three showed large polyps, four showed small polyps, and 12 were normal. Inter-observer variation was compared using odds ratios with the trainee group as reference (baseline group).

RESULTS

Experts were significantly more likely to correctly identify neoplasia on DCBE than trainees. The odds of a correct diagnosis for experts were 2.79 (95% CI 2.04, 3.81) for cancer, 2.36 (1.88, 2.97) for large polyps, and 3.50 (1.98, 6.18) for small polyps. While consultants were more likely to correctly diagnose a large polyp than trainees, 1.45 (1.15, 1.84), there was no significant difference between these two groups for the correct diagnosis of either cancer, 1.24 (0.52, 2.96), or small polyps, 1.26 (0.83, 1.90). A cancer was missed by 6 (60%) experts, 9 (90%) consultants, and 8 (80%) trainees. Large polyps were missed by 4 (40%) experts, 5 (50%) consultants, and 6 (60%) trainees. There was no significant difference between any group when false positive diagnoses were considered.

CONCLUSIONS

There is considerable inter-observer perceptive error for the diagnosis of neoplasia on DCBE. Experts performed significantly better than other observers but the overall standard of performance was poor, even amongst experts.

Options for screening for colorectal cancer

Unlike other types of cancer, there are several options for screening for colorectal cancer (CRC). The most extensively examined method, faecal occult blood testing (FOBT), has been shown, in three large randomized trials, to reduce mortality from CRC by up to 20% if offered biennally and possibly more if offered every year. Recently published data from the US trial suggest that CRC incidence rates are also reduced by up to 20%, but only after 18 years. In this study, the number of positive slides was associated with the positive predictive value both for CRC and adenomas larger than 1 cm, suggesting that the reduction in CRC incidence was caused by the identification and removal of large adenomas. In this respect, this study supports the concept that removing adenomas prevents CRC. More efficient methods of detecting adenomas include the use of colonoscopy or flexible sigmoidoscopy (FS). Considerable evidence exists from case-control and uncontrolled cohort studies to suggest that endoscopic screening by sigmoidoscopy reduces incidence of distal colorectal cancer. However, in the absence of evidence from a randomized trial, several countries have been reluctant to introduce endoscopic screening. Three trialsare currently in progress (in the UK, Italy and the US) to address this issue. Two of these trials are examining the hypothesis that a single FS screen at around age 55-64 might be a cost-effective and acceptable method for reducing CRC incidence rates. Recruitment and screening are now complete in both studies and the first analysis of results on incidence rates is expected in 2004. Colonoscopy screening at 10-year intervals has recently been endorsed in the US on the basis that the reductions in incidence observed with distal CRC screening can be extrapolated to the proximal colon. However, data are lacking and a pilot study for a trial of the acceptability and efficacy of colonoscopy screening is in progress in the US. It has also been suggested that FOBT testing should be used to detect proximal CRC missed by sigmoidoscopy screening, but the small amount of published data suggest that supplementing FS with FOBT offers very little advantage over FS alone. Other forms of CRC screening are under investigation and represent exciting options for the future. Extraction of DNA from stool is now feasible and a number of research groups have shown high sensitivity for CRC using a panel of DNA markers including mutations in k-ras, APC, p53 and BAT26. Data so far indicate that, with the exception of k-ras, these markers are highly specific and therefore represent a significant improvement over FOBT. Whether these tests will replace or supplement existing methods of screening has yet to be determined. It has been suggested that BAT26, which is a marker of microsatellite instability, a feature of proximal sporadic CRC, might be a useful adjunct to sigmoidoscopy screening. Others have suggested that a test for occult blood should be included with the DNA markers to further increase sensitivity. It is not yet known how sensitive these markers are for adenomas--it is only by detecting adenomas that CRC incidence rates can be reduced. A final exciting new option for screening is virtual colonoscopy (VC), which by screening out people without neoplasia allows colonoscopy to be reserved for patients requiring a therapeutic intervention. The sensitivity of VC for large adenomas and CRC appears to be high, although results vary by centre and there is a steep learning curve. Sensitivity for small adenomas is low, but perhaps it is less essential to find such lesions. Some groups have suggested that virtual colonoscopy might be a useful option for investigating patients who test positive with stool-based screening tests. Whichever CRC screening method is finally chosen (and there is no reason why several methods should not ultimately be available), high quality endoscopy resources will always be required to investigate and treat neoplastic lesions detected.

Use of multidetector-row computed tomographic colonography before flexible sigmoidoscopy in the investigation of rectal bleeding

Selective colonography may reduce need for colonoscopy

Optimizing bowel preparation for multidetector row CT colonography: effect of Citramag and Picolax

AIM

To compare the adequacy and acceptability of Picolax and Citramag bowel cleansing agents for CT colonography.

MATERIALS AND METHODS

Multidetector row CT colonography was performed in 124 subjects; 43 had been prepared with Picolax and 81 with Citramag. Datasets were assessed for retained fluid and solid residue, and overall adequacy of segmental visualization. Preparation acceptability was also assessed.

RESULTS

There was significantly less retained fluid with Picolax. The odds of being in the next higher category for retained fluid when using Picolax were 0.33 (CI: 0.22-0.50, p<0.0001) when compared with Citramag, for all segments combined. However there was significantly more retained solid residue with Picolax. The odds of being in the next higher category for retained residue when using Picolax were 2.44 (CI: 1.41-4.24, p=0.002) when compared with Citramag, for all segments combined. There was no significant difference with respect to overall segmental visualization: the odds of a segment being adequately visualized when using Picolax were 1.52 (CI: 0.88-2.65, p=0.14) when compared with Citramag. There was no significant difference with respect to acceptability.

CONCLUSION

Picolax results in a significantly drier colon than Citramag and associated with more retained residue. We found Picolax the more suitable preparation for CT colonography.

Socioeconomic variation in participation in colorectal cancer screening

OBJECTIVES

To investigate socioeconomic variation in participation in flexible sigmoidoscopy (FS) screening for colorectal cancer.

DESIGN

A prospective study nested within a multicentre randomised controlled trial of the efficacy of FS screening for the prevention and early detection of colorectal cancer (the UK flexible sigmoidoscopy trial).

SETTING

Glasgow, Scotland.

PARTICIPANTS

55-64 year old adults, registered with general practitioners participating in the FS trial.

MAIN OUTCOME MEASURES

Screening participation measured at three levels: questionnaire return; interest in screening; attendance at screening.

RESULTS

Socioeconomic deprivation was a strong predictor of participation. Return of the screening questionnaire, expression of interest in screening, and attendance at the test, were all lower in more deprived groups.

CONCLUSIONS

These results highlight the need to consider ways to reduce inequalities in screening uptake, in parallel with the introduction of any new screening programmes, to avoid exacerbating social gradients in cancer mortality.

Declining the offer of flexible sigmoidoscopy screening for bowel cancer: a qualitative investigation of the decision-making process

Qualitative methods were used to investigate decision-making among a group of older adults who declined the offer of flexible sigmoidoscopy screening for bowel cancer. Interviews were conducted with 60 people (30 men and 30 women) who either had not responded to the screening letter or who responded saying that they were not interested in participating. The findings suggest that low perceived susceptibility to bowel cancer, in terms of current health status, family history or absence of bowel symptoms. was an important factor in the decision to decline screening. Procedural barriers such as embarrassment, pain/discomfort and perceived unpleasantness of the test were reported as relatively minor, although the test was considered more physically intrusive than other screening tests. Avoidant attitudes emerged as an important theme and were reported by a third of respondents. Distinct patterns of decision-making were also observed and three groups emerged from accounts: (i) forgetting or avoiding making a decision about the test (ii) a confident rejection of the test based on a few salient factors, and (iii) a more careful consideration of the test focusing on issues of susceptibility. The findings are discussed in the context of models of health behaviour and bowel cancer screening participation research.

Predictors of attendance in the United Kingdom flexible sigmoidoscopy screening trial

OBJECTIVE

To investigate predictors of attendance in the United Kingdom flexible sigmoidoscopy screening trial.

DESIGN

Prospective design in which participants completed a postal questionnaire before being sent their invitation for screening.

SETTING

Welwyn Garden City and Leicester, United Kingdom.

PARTICIPANTS

A total of 2758 patients aged 55 to 64, registered with general practices in the two centres, who (a) expressed interest in having the screening test, (b) completed a postal questionnaire, and (c) were subsequently invited for screening.

MAIN RESULTS

The attendance rate among questionnaire responders was 76.1%. Multiple logistic regression analysis yielded a final model that included nine independent predictors of attendance. Patients with the following characteristics were more likely to attend: men; home owners; non-smokers; those who had regular check ups at the dentist; those with better subjective health; those who minded less about having medical tests; those who said they would definitely rather than probably take up the offer of sigmoidoscopy screening; and those who perceived less barriers and more benefits to having the test.

CONCLUSIONS

The findings are broadly consistent with previous studies of screening participation, although subjective health emerged as an important predictor in this study. There was no evidence for "reverse targeting": attenders were not at lower (or higher) risk for colorectal cancer compared with non-attenders. The findings relating to attitudes and beliefs could be used in efforts to improve attendance, for example by developing information leaflets that address barriers to screening. Other findings could be used to target interventions to subgroups that have relatively low rates of screening participation.

Psychosocial influences on older adults' interest in participating in bowel cancer screening

BACKGROUND

As part of a multicenter, randomized controlled trial of the efficacy of flexible sigmoidoscopy for the prevention of bowel cancer, an investigation of the predictors of screening interest was carried out in a subsample of older adults.

METHOD

The aim of the study was to establish the predictive power of the Health Belief Model (HBM) and to evaluate the contribution of HBM elements in mediating the effect of other demographic and health variables which have been found to be associated with screening interest and participation. A total of 5,099 participants were sent a postal questionnaire which examined screening interest, attitudes toward screen ing (benefits and barriers), perceived bowel cancer risk, bowel cancer worry, bowel symptoms, health status, state anxiety, and optimism. A total of 3,648 questionnaires were returned completed, giving a response rate of 71.5%.

RESULTS

The results showed that threat, barriers, and benefits explained 47% of the variance in interest. Demographic and health variables were also associated with screening interest, although most of their effect was mediated by the HBM constructs.

DISCUSSION

This community study in older adults showed a high level of interest in participating in screening. The large sample size provided the opportunity to test the value of the HBM model and to examine mediation of demographic and health variables. The HBM proved to be a good model of screening interest. These results further our understanding of the decision processes in participating in cancer screening and point to directions to increase the level of participation in community samples.

Germline APC variants in patients with multiple colorectal adenomas, with evidence for the particular importance of E1317Q

Mendelian tumour syndromes are caused by rare mutations, which usually lead to protein inactivation. Few studies have determined whether or not the same genes harbour other, more common variants, which might have a lower penetrance and/or cause mild disease, perhaps indistinguishable from sporadic disease and accounting for a considerable proportion of the unexplained inherited risk of tumours in the general population. Germline variants at the APC locus are excellent candidates for explaining why some individuals are predisposed to colorectal adenomas, but do not have the florid phenotype of familial adenomatous polyposis. We have screened 164 unrelated patients with 'multiple' (3-100) colorectal adenomas for germline variants throughout the APC gene, including promoter mutations. In addition to three Ashkenazi patients with I1307K, we found seven patients with the E1317Q variant. E1317Q is significantly associated with multiple colorectal adenomas (OR = 11. 17, 95% CI = 2.30-54.3, p < 0.001), accounting for approximately 4% of all patients with multiple colorectal adenomas. In addition, four patients with truncating APC variants in exon 9 or in the 3' part of the gene were identified. Germline APC variants account for approximately 10% of patients with multiple adenomas. Unidentified predisposition genes almost certainly exist. We argue that it is worthwhile to screen multiple adenoma patients for a restricted number of germline APC variants, namely the missense changes E1317Q and I1307K (if of Ashkenazi descent), and, if there is a family history of colorectal tumours, for truncating mutations 5' to exon 5, in exon 9 and 3' to codon 1580.

Acceptability of flexible sigmoidoscopy screening in older adults in the United Kingdom

OBJECTIVES

To assess the acceptability of bowel cancer screening using flexible sigmoidoscopy (FS).

SETTING

Adults aged 55 to 64 recruited from general practices in Welwyn Garden City and Leicester, which were the pilot and start up centres of a multicentred randomised controlled trial of FS screening (the ICRF/MRC Flexible Sigmoidoscopy Screening Trial).

METHODS

Screenees (n=4422) were sent a three month follow up questionnaire that included measures of satisfaction with information given before the test, facilities at the test unit, attitudes of the staff, and explanation of the results. Measures of pain, embarrassment, feelings of being "in control" during the test, willingness to encourage others to have the test, and gladness to have participated were also included. In addition, semistructured telephone interviews were conducted with 60 screenees, stratified by screening outcome and gender.

RESULTS

The follow up questionnaire was completed by 94% of screenees. Responses indicated a high level of satisfaction with the procedure: 99% were satisfied with the information given before the test, the facilities, the attitudes of the staff, and the explanation of their results; 91% reported only mild or no pain; 97% reported little or no embarrassment; and 99% were glad they had the test. Satisfaction ratings varied little by gender or outcome group. The quantitative results were reinforced by the qualitative data, which also revealed high acceptability.

CONCLUSION

In the context of a clinical trial with dedicated trial staff, FS is a well tolerated procedure. There are high levels of satisfaction with service provision and positive attitudes towards the programme.

Estimating time and travel costs incurred in clinic based screening: flexible sigmoidoscopy screening for colorectal cancer

OBJECTIVES

To identify the characteristics of mode of travel to screening clinics; to estimate the time and travel costs incurred in attending; to investigate whether such costs are likely to bias screening compliance.

SETTING

Twelve centres in the trial of flexible sigmoidoscopy screening for colorectal cancer, drawn from across Great Britain.

METHOD

Analysis of 3525 questionnaires completed by screening subjects while attending clinics. Information supplied included sociodemographic characteristics, modes of travel, expenses, activities foregone owing to attendance, and details of companions.

RESULTS

More than 80% of subjects arrived at the clinics by car, and about two thirds were accompanied. On average, the clinic visit involved a 14.4 mile (22.8 km) round trip, requiring 130 minutes. Mean travel costs amounted to 6.10 Pounds per subject. The mean gross direct non-medical and indirect cost per subject amounted to 16.90 Pounds, and the mean overall gross cost per attendance was 22.40 Pounds. Compared with the Great Britain population as a whole, non-manual classes were more strongly represented, and the self employed less strongly represented, among the attendees.

CONCLUSIONS

In relation to direct medical costs, the time and travel costs of clinic based screening can be substantial, may influence the overall cost effectiveness of a screening programme, and may deter potential subjects from attending.

Intravenous antispasmodic and patient-controlled analgesia are of benefit for screening flexible sigmoidoscopy

The possible benefits of premedication with the antispasmodic hyoscine n-butyl bromide (hyoscine) and analgesia with inhaled nitrous oxide/oxygen mixture (nitrous oxide) were assessed in a double-blinded, placebo-controlled trial. Consecutive patients at normal risk for cancer undergoing screening flexible sigmoidoscopy were randomly allocated to receive either (1) intravenous hyoscine 20 mg plus inhaled oxygen on demand (n = 40), (2) sterile water injection plus inhaled nitrous oxide on demand (n = 48), or (3) sterile water injection plus inhaled oxygen on demand (n = 43). One recently trained primary care physician performed all procedures. Duration of the procedure, endoscopic findings, and depth of insertion were recorded. After the examination, screenees rated their degree of pain during the procedure using a visual analogue scale. Depth of insertion did not differ between the three study groups, but the duration of the procedure was significantly less in the hyoscine group (median, 12.5 minutes) as compared with placebo (median, 18 minutes; p = .0008). Fifty-four percent of screenees chose to use the on-demand gas. Pain scores were significantly lower in those individuals who inhaled nitrous oxide as compared with placebo (p = .045). Premedication with antispasmodic shortens total procedure time for flexible sigmoidoscopy by a moderately experienced endoscopist as compared with placebo. In this study, a significant number of screenees experienced discomfort during flexible sigmoidoscopy, which appeared to be reduced by offering nitrous oxide inhalation.